#define _CRT_SECURE_NO_WARNINGS 1
#include<stdio.h>
int main()
{
	int a, b, c, d;
	scanf("%d %d %d %d", &a, &b, &c, &d);
	if (a < b)
	{
		int tep = 0;
		tep = a;
		a = b;
		b = tep;
	}
	if (a < c)
	{
		int tep = 0;
		tep = a;
		a = c;
		c = tep;
	}
	if (a < d)
	{
		int tep = 0;
		tep = a;
		a = d;
		d = tep;
	}
	printf("%d", a);
	return 0;
}






























